1. Field
One embodiment of the invention relates to a sound-reproducing apparatus for reproducing compressed audio data having MP3 or the like, and more particularly to a sound-reproducing apparatus for executing interpolation processing for high frequencies during sound reproduction, and a high frequency interpolation-processing method for use therein.
2. Description of the Related Art
A frequency sample interpolator which reads out auxiliary information of compressed audio data, and specifies a band of high frequency components which are lacked when compression processing is executed, thereby interpolating the lacked high frequency components has been known as a conventional art. This frequency sample interpolator, for example, is disclosed in the Japanese Patent Kokai No. 2004-198485.
According to this frequency sample interpolator, in the case of, for example, MPEG-1 or AUDIO Layer2, an amount of data allocated, for each band, which is contained in the auxiliary information is read out, or in the case of, for example, MPEG-2 or AUDIO NBC, scale factor band information representing the highest band having frequency components existing therein is read out, whereby it is possible to specify a precise signal lack band.
However, according to the conventional frequency sample interpolator, the auxiliary information must be read out every frame constituted by a predetermined number of samples, and thus the auxiliary information must be analyzed. As a result, an operation process becomes complicated and thus a large burden is imposed on processing.